Gas regulator for firearms



Feb 2Q, E945 J. c* GARAND 29%@5559 GAS REGULATOR FOR FIREARMS Filed Aug. 3, 1942 Patented Feb. 2G, 1945 GAS REGULATOR FOR FIREARMS .lohn C. Gal-and, Springfield, Mass. Application August 3, 1942, Serial N0. 453,425

(Granted under the act of March 3, 1883, as amended April 3i), 1928; 370 O. G. 757) 2 Claims.

The invention described herein may be manuiactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.

This invention relates to a gas regulator 4for a firearm.

Certain gas-operated firearms have no adjustment for regulating the energy imparted by the actuating gases impinging on the piston. Control of these'gases is very desirable because of the iiuctuation of the pressures of these gases when using diierent kinds or lots of ammunition. It is especially desirable to have some regulating means to allow for the escape of excessive high pressure gases and any accumulation of powder residue and carbon attendant with the actuating gases. Ammunition which develops pressures vconsiderably in excess of normal operating pressures produces a violent reaction on the operating I,

mechanism of the firearm which, if continually repeated, may produce breakage of certain components. Powder residue and carbo-n deposits on the piston and within the cylinder necessitate frequent cleaning of the piston and gas cylinder to maintain proper functioning of the rearm.

Accordingly, it is an object of this invention to provide a method and apparatus for controlling the energy imparted by the actuating gases of gas-operated rearms.

Another object of this invention is to control the energy imparted by the actuating gases of gas-operated rearms 'by a gas diversion means.

Still another object of this invention is to provide means to substantially eliminate any accumulation of powder residue and carbon within the gas cylinder of a rearm.

A particular object of this invention is to provide gas regulating means for a riile such as disclosed in U. S. Patent No. 1,892,141 to John C. Garand.

The specific nature of the invention as well as other objects and advantages thereof will clearly appear from a description of a preferred embodiment as shown in the accompanying drawing in which: l

Fig. 1 is a longitudinal sectional view of a gas cylinder assembled to a firearm barrel showing the gas lcylinder lock screw which embodies this invention secured to the end of the gas cylinder.

Fig. 2 is a longitudinal sectional view of the gas cylinder lock screw as shown in Fig. 1.

Fig. 3 is another longitudinal sectional view of the gas cylinder lock screw as shown in Fig. 1 taken on a plane 3--3 at right angles to the longitudinal sectional view as shown in Fig. 2.

Fig. 4 is a cross Ysectional view of the gas cylinder lock screw taken along the plane 4-4 of v Fig. 2.

Fig. 5.is a cross sectional View of the gas cylinder lock screw taken along the plane 5-5 'of Fig. 2. i

Fig. 6 is a right end elevational view of the gas cylinder lock screw as shown in Fig. 3.

in Fig. 1 there is shown a gas cylinder screw I embodying this invention assembled to the end of a gas cylinder 2 of the type disclosed in U. S. Patent No. 1,892,141 to John C. Garanti. The gas cylinder 2 is suitably mounted on a barrel 3 and a cooperating piston is slidably mounted within the gas cylinder 2. A gas port 5 provided in the gas cylinder 2 is in alignment with the gas port 6 provided in the barrel 3. An operating spring 'I is suitably mounted behind the piston 4.

The gas cylinder screw I (Fig. 2) comprises a hollow `cylindrical body' ia and an integral cylindrical head Ib. A threaded portion Ic is provided on the exterior periphery of the shank end of the lock screw I to secure the screw I to the gas cylinder 2, Anaxial threaded hole 9 is provided in the shank end of screw I. This hole extends inwardly about one-half the length of the lock screw l. An annular groove I0 is provided at the bottom of the hole 9 for manufacturing convenience to produce a squared bottom surface. Another annular groove II is provided approximately in the center of the hole il. The grooves I0 and II are of slightly larger diameter than the threaded hole 9. An axial hole I2 is provided in the lock screw I extending from the face of the head Ib into the hole il. On each side of the hole I2 and connecting therewith there are provided two opposed smaller holes Ill and I5 which pass through the gas cylinder lock screw I down through the groove II.

A set screw I3 having a socket wrench recess IG in its head is threadably inserted in the hole 9 with the socket recess I5 facing towards the head I b. The screw I3 is screwed into hole 9 until the end 43a of the screw I3 projects slightly into the space defined by groove Il. A plug Il is threadably inserted into the front end of hole S. This plug projects only a very short distance into the groove II. A longitudinal hole I3 is centrally provided in the plug ll. The end Ia of hole I8 adjacent the groove II is conically counteiibored. A pin 20 inserted in a suitable hole I9 provided on the edge of hole 9 secures the plug Il to the screw I. The surface Ila of plug Il is ground ci flush with the end I d of the lock screw I and is highly polished to prevent the adherence of carbon. The end |3a of screw I3 and the end Hb of plug I1 are suitably ground so that when the screw I3 is screwed down to meet the plug I'I perfect contact will be made between the two mating surfaces.

By inserting a socket wrench into the socket I6 of the screw I3, the screw I3 may be read ily turned downward to contact the surface Hb of the plug Il. In this position the lock screw I is in effect a solid memberv and therefore no gas can escape from the cylinder 2 outwardly through the gas cylinder lock screw I. However, when the screw I3 is backed oft of the surface I1b, a gas passage will then be opened. The gas may now escape from the hole I8 into the recess formed by the groove II and then pass out, the holes i4 and I5, which as previously mentioned, extend down into the groove II.

When shooting a rearm with ammunition which develops higher pressure than desired, the

sidue or carbon within the cylinder will be blown out through the holes I4 and I5 when the gas port I8 is open.

I claim:

1. In a gas cylinder for an automatic'rearm, a pressure regulating member comprising a plug adapted to be threaded into the interior of the cylinder, said plug having an axial hole extending therethrough, said hole having a threaded counterbored portion in one end, a valve member threaded into the bottom of the counterbored threaded portion of said hole, means in said valve member arranged to receive a tool for rotating said valve member, a second valve member secured in the outer end of the counterbored rthreaded portion of said hole said second valve member having an axial gas passage therethrough, the adjacent surfaces of said rst valve rearward movement of the recoiling mechanism f of the firearm will be somewhat violent. While not necessarily harmful to the gun the timing of the feed is quite often upset with resultant malfunctions. Therefore, if it is determined that the pressure being developed by the ammunition is excessive with hole I8 blocked by the screw I3, this pressure may be readily reduced by backing 01T the screw I3 to provide an exhaust Dassage for the gas through the hole I8 and the holes i4 and I5. Thus when the cartridge is tired, a portion of the actuating gases impinging on the end of piston 4 will be diverted through the hole I8, thereby reducing the full amount of the force that would otherwise impinge on the end of piston 4 when the gas port I8 is closed.

It should be understood that only a small portion of the actuating gases pass out through the gas port I8 when the screw I3 is in the open position and therefore the remaining energy of the actuating gases is still ample to satisfactorily operate the mechanism of the firearm. It may be readily seen that by providing diierent diameters of the gas port I, greater or lesser escape of gas may thereby be provided. It is also apparent that any accumulation of powder remember and said second valve member being constructed and arranged to seal said gas passage by rotation of lsaid irst valve member Within the counterbored threaded portion of said hole, an annular recess in said plug located adljacent the plane of engagement of the said ad- 'jacent surfaces of said first and said second valve members, and an exhaust passage through said plug connecting with said annular recess.

`2. In a gas cylinder for an automatic rearm, a pressure regulating member comprising a plug adapted to be threaded into the interior of the cylinder, said plug having an axial hole extending therethrough, a valve member threaded into said hole, and adapted to be rotated therein, a second kvalve member secured in said hole adjacent the first-named valve member and having an axial gas passage therethrough, the adjacent Surfaces of said valve members being constructedI and arranged to, seal said gas passage by rotation of said first-named valve member,y an annular recess in said plug located adjacent the Plane Of engagement of the said adjacent surfaces o thev valve members, .and an exhaust passage through said plug connecting with said annular recess.

JOHN C. 

